One recent night, my daughter Dahlia and I popped out for pizza, and while we were chatting over our slices, CBSEvening News came on the television suspended over the counter. We sat transfixed by a segment on a massive number of homeless families that have settled in a makeshift community in the California desert. Dahlia chewed thoughtfully as she watched a father tell the reporter about how he had worn a tie to work until six months ago, when he lost everything and had no choice but to move there with his three kids. Then she shifted her eyes to me and asked, “Mama, that won’t be us because there’s only one of me instead of three?”

She’s on to something. According to the USDA, a child born in 2011 will cost an average of $234,900 to raise to age 18. If your household income is over $100,000, you can raise that number to about $390,000. Yes, there are some savings after the first child — you don’t have to buy another high chair! — but it’s not as though you get a huge volume discount on subsequent offspring. There are also opportunity costs of a mother’s loss of income from parental leave, scaling back hours or dropping out of the workforce entirely. No wonder, according to the USDA, two-parent households with two children devote over one-third of their income to their kids. Add it all up and there’s a strong economic case for stopping at one child.

And yet the world will tell you — from grandmothers to sitcoms to strangers in the supermarket — that money shouldn’t be a factor in deciding to have more children. If you express concern about how much children cost, then you’ve clearly got your priorities wrong. You’ll make it work, they tell you. Don’t be selfish. (I wrote about this and other stereotypes of parents with singletons in a cover story for TIME.)

There’s a popular theory of economics that contends that there’s really no difference between deciding to raise a child and making any other investment. Kids, like anything else, the thinking goes, are a form of capital that yield a future flow of valuable services. Which, if you have land to farm, makes perfect sense; less so, I’d say, in the modern world. If that’s how people make the choice to become parents and to have additional children, I’ve yet to meet any. However you might identify the impulse to bring a child into your family, to love and tend a new and growing life, it’s probably not a cost-benefit analysis.

But why do we need to present a rationale for the decision to devote our resources — whether they are financial or that ultimately luxury, time — to something other than children? What’s wrong with devoting your energy to one wonderful kid while sparing some to travel, maintain friendships, read a novel and be a more engaged citizen, not to mention not stretching yourself until you snap just to get your damn work done each week? Considering the greater flexibility that stopping at one kid allows, it’s no surprise that in a University of Pennsylvania study of 35,000 mothers, those raising only children were the happiest, with each additional child reducing a mother’s well-being.

Last week, our stove started to fail, and the three of us went to an appliance store to find a replacement. The salesman told me about people who come in week after week, armed with issues of Consumer Reports and cost comparisons. It occurred to me then, as it has many times before, that people agonize and weigh their options about such domestic choices much more than they do about the decision to have a second or third child.

If it’s what their hearts are telling them to do, I understand. But if it’s that culture aggressively recommends having more than one child, that’s another issue. If the stigma of raising an only child were to dissipate — and if parents didn’t feel shamed for wanting to use their precious resources elsewhere — perhaps people would make different choices. Perhaps they’d learn, like I have, that we don’t need to stretch ourselves more than we have to.